Spark plug



July 29, 1941. e. s. WEINERTH SPARK PLUG Filed Jan. 9, 1940 4 IFIG. a-

INVENTOR. Genus: 5. WEINERTH 7 ATTORNEY.

Patented July 29, 1941 UNITED STATES PATENT OFFICE SPARK PLUG George S. Weinerth, Reading, Pa.

Application January 9, 1940, Serial No. 313,036

18 Claims.

This invention relates to a spark plug, and has particular reference to a spark plug so designed that it has not only greater efficiency over a wider range, but has greater life than ordinary conven-- tional spark plugs of the present day.

This invention is an improvement Over the spark plug shown and described in my co-pending application Serial No. 245,368, filed December 13, 1938, and in which there is shown a type of spark plug in which the end of the insulator extends beyond the end of the shell so that the sparking occurs well in the gas filled chamber, and such plug is so arranged that the distance of travel from the positive electrode to metal for heat dissipation is extremely short.

This present spark plug embodies all the advantages of the plug shown in said application as well as other advantages which will be disclosed herein.

The object of the present invention is to provide a spark plug in which the electrodes extend fairly within the compressed gas chamber.

Another object of the invention is to provide a spark plug in which the distance of travel from the positive electrode to metal for heat dissipation is very short.

A still further object of the invention is to provide a spark plug which has substantially no pockets between the insulator and shell wherein waste gases may collect.

A still further object of the invention is to provide a spark plug so arranged that a turbulent action of the gases takes place between the end of the insulator and the end of the shell, thereby keeping the insulator clear of carbon deposits so as to insure a fixed hot spark at all times.

The drawing illustrates an embodiment of the invention, and the views therein are as follows: Figure l is a vertical sectional view of a spark plug constructed according to my invention, and is of the crimped type,

Figure 2 is a fragmentary vertical sectional view of the bottom of the shell on an enlarged scale,

Figure 3 is a fragmentary vertical sectional view of the bottom of the insulator showing the positive electrode therein, and

Figure 4 is a fragmentary vertical sectional view of a spark plug showing modified electrodes.

As illustrated in the drawing, the shell 6 is of r the crimped type, although it is to be understood that the invention relates not only to this type of plug but to all types including the sealing nut type. Extending through the shell 6 is an insulator I. The insulator has a central longitudinal hole 8 through which the positive electrode 9 extends, and this electrode is provided with a screw threaded portion II which is cemented into an enlarged opening l2 by the cement l3, while a washer I4 bears against the upper end of said insulator, and a screw it extends outward therefrom for the purpose of connecting a terminal to said spark plug. The insulator has an enlarged body portion l'l fitting into the enlarged opening I8 of the shell, and this body portion is reduced, as at i9, by a tapered shoulder 20. This shoulder is of the same taper as the shoulder 2| on the shell 6, and the reduced portion l9 fits within a reduced opening 22 in the shell, and has a tapered shoulder 23 terminating in a tapered tip 24. The shoulder 23 is of the same taper as the taper 26 of the shell, and a gasket 21 rests between said last-named shoulders for the purpose of providing a good contact between the insulator and metallic shell,

Referring now to Figure 2, which is an enlarged view, the tapered shoulder 26 of the shell has another tapered surface 28 extending towards the firing end of said plug and to a concentric surface 29. Between this concentric surface 29 and the firing end of the shell is an outwardly flaring tapered surface 3!. The arrangement of the parts can probably best be understood by reference to Figure 4. Here it is seen that the tapered shoulder 23 of the insulator bears against the gasket 2'! on the tapered shoulder 2t of the shell.

The tapered surface 28 is uncovered and the concentric surface 29 forms with the tapered tip 24 of the insulator a tapered channel 32. When the plug is screwed into a cylinder block by virtue of the threads 34, the extended end 33 of the electrode 9 will extend well into the cylinder so that when it is filled with compressed combustion gases, the spark will occur across that terminal and the ground terminal 36 which is secured to the shell 6, and consequently, the ignition of the gases in the chamber will be instantaneous.

Figure 4 shows a type of electrode where the end thereof comprises a disk 31 brazed or welded to the electrode 9, and this disk may be substantially the same diameter as the end of the insulator tip 24. Where a positive electrode of this type is used, the ground electrode 38 will have its horizontal arm 39 extended across the disk end 31 of the positive electrode so that a broader sparking area is provided.

It has been found that by providing the flaring collects within said flaring surface or said channel.

It is also a part of this invention that the distance between the end of the insulator tip 24 and the contact to metal through virtue of the gasket 21 is quite short, but still suiflcient so that the spark plug will not run cold, and on account of this shortened path of travel, the spark plug will not overheat so as to continue to provide explosion in the cylinder even after the ignition has been cut off.

By the arrangement of parts as shown in the drawing and described herein, there is a much better heat regulation, and this dissipates any gaseous deposits on the insulator tip or in the channel.

Of course, the spark plug illustrated and described herein may be modified in various ways without departing from the invention herein set forth and hereafter claimed.

The invention is hereby claimed as follows:

1. A spark plug having a metallic shell and an insulator having a tapered end extending outward from said shell, and a concentric surface in said shell and around a part of the tapered end of said insulator.

2. A spark plug having a metallic shell and an insulator, said shell at the firing end of said plug having an outwardly flaring tapered surface, a concentric surface beyond said flaring surface, and a tapered end on said insulator extending from said shell and providing with said concentric surface a tapered channel.

3. A spark plug comprising a metallic shell, an

insulator, a positive electrode extending through said insulator, a ground electrode, a tapered shoulder in said shell and a complementary shoulder on said insulator, a gasket between said shoulders, a concentric surface in said shell terminating in an outwardly flared surface at the firing end of said shell, and a tapered end on said insulator providing with said concentric surface a tapered channel.

4. A spark plug comprising a metallic shell, an insulator, a positive electrode extending through said insulator, a ground electrode, a tapered shoulder in said shell and a complementary shoulder on said insulator, a gasket between said shoulders, a concentric surface in said shell terminating in an outwardly flared surface at the firing end of said shell, a tapered surface in said shell between said tapered shoulder and said concentric surface, and a tapered end on said insulator providing with said concentric surface a tapered channel.

5. A spark plug including a metallic shell and an insulator, said shell having at its firing end an outwardly flaring surface, a concentric surface beyond said flaring surface, a tapered surface beyond said concentric surface, and a tapered shoulder beyond said tapered surface, a complementary shoulder on said insulator, and a tapered end on said insulator extending through said tapered surface, concentric surface and flaring surface and out from the end of said shell.

6. A spark plug having a metallic shell, an insulator, a positive electrode extending through said insulator and having a disk on the end thereof and abutting the end of said insulator, said insulator end being tapered, a concentric surface in said shell forming with the tapered end of said insulator a tapered channel, and a ground electrode extending from said shell and across said disk.

7. A spark plug having a metallic shell, an

insulator, a positive electrode extending through said insulator and having a disk on the end thereof and abutting the end of said insulator, said insulator end being tapered, said shell at the firing end of said plug having an outwardly flaring tapered surface, a concentric surface in said shell beyond said flaring surface and forming with the tapered end of said insulator a tapered channel, and a ground electrode extending from said shell and across said disk.

8. A spark plug having a metallic shell, an insulator, a positive electrode extending through said insulator and having a disk on the end thereof and abutting the end of said insulator,

. said shell having at its firing end an outwardly flaring surface, a concentric surface beyond said flaring surface, a tapered surface beyond said concentric surface, and a tapered shoulder beyond said tapered surface, a complementary shoulder on said insulator, a tapered end on said insulator extending through said tapered surface, concentric surface and flaring surface and out from the end of said shell, and a ground electrode extending from said shell and across said disk.

9. A spark plug having a metallic shell, an insulator, a positive electrode extending through said insulator and having a disk on the end thereof and abutting and substantially the same diameter as the end of said insulator, said insulator end being tapered, a concentric surface in said shell forming with the tapered end of said insulator a tapered channel, and a ground electrode extending from said shell and across said disk.

10. A spark plug having a metallic shell, an insulator, a positive electrode extending through said insulator and having a disk on the end thereof and abutting and substantially the same diameter as the end of said insulator, said insulator end being tapered, said shell at the firing end of said plug having an outwardly flaring tapered surface, a concentric surface in said shell beyond said flaring surface and forming with the tapered end of said insulator a tapered channel, and a ground electrode extending from said shell and across said disk.

11. A spark plug comprising a metallic shell having an external threaded portion for attaching same, an insulator, a positive electrode extending through said insulator, a ground electrode, a tapered shoulder in said shell, a complementary shoulder on said insulator, said shoulders located intermediate of said threaded portion, a gasket between said shoulders providing contact between said insulator and shell at a point in close proximity to the firing end of said plug, a concentric surface in said shell terminating in an outwardly flared surface at the firing end of said shell, and a tapered end on said insulator providing with said concentric surface a tapered channel.

12. A spark plug having a metallic shell and an insulator having a reduced end extending outwardly from said shell, a concentric surface in said shell in spaced relation to and around a part of the reduced end of said insulator, and a sealing gasket engaging the shell and insulator at a distance from the firing end of the shell not greater than the thickness of said reduced end.

13. A spark plug having a metallic shell and an insulator having a reduced end of circular cross-section extending outwardly from said shell, a concentric surface in said shell and around a part of the reduced end of said insulator forming a narrow channel therebetween, and means sealing said channel at a distance from the firing end of the shell not in excess of the diameter of said reduced end.

14. A spark plug having a metallic shell and an insulator, said shell at the firing end of said plug having a slightly enlarged portion, a concentric surface beyond said enlarged portion, a reduced end of circular cross-section on said insulator spaced from said concentric surface and providing a channel therebetween, and means sealing said channel at a distance from the firing end of the shell less than the thickness of said reduced end.

15. A spark plug having a metallic shell, an insulator, a positive electrode extending through said insulator and having a disk on the end thereof and abutting the end of said insulator, said insulator end being of reduced circular crosssection, a concentric surface in said shel1 in spaced relation to the reduced end of said insulator to form a channel therebetween, and a ground electrode extending from said shell and across said disk.

16. A spark plug comprising a metallic shell having an externally threaded portion initiating at the firing end of said shell for attaching same, an insulator, a positive electrode extending through said insulator, a ground electrode, a tapered shoulder in said shell, a complementary shoulder 'on said insulator, said shoulders being located adjacent the firing end of said plug and within the threaded portion, a gasket between said shoulders providing contact between said insulator and shell, a reduced end of circular crosssection on said insulator spaced from the shell to form a channel therebetween, and the reduced insulator end extending outwardly from said shell.

17. A spark plug having a metallic shell and an insulator, said insulator comprising a reduced end terminating in a lower upwardly and outwardly inclined shoulder, an enlarged portion beyond said shoulder including an upper inwardly and upwardly inclined shoulder, the shell having a bore at the firing end through which the reduced insulator end is extended in closely spaced relation, a shoulder complementary to said insulator lower shoulder, a concentric surface in closely spaced relation to the insulator enlarged portion, an upper shoulder complementary to the insulator upper shoulder, a pair of sealing gaskets maintaining the shell and insulator shoulders in spaced relation, and the upper shoulder of the shell overlying its associated gasket to maintain the shell and insulator in assembled relation.

18. A spark plug comprising a metallic shell, an insulator having an enlarged portion and a reduced end of circular cross-section extending outwardly from said shell, a sealing gasket engaging said shell and insulator at a point spaced from the firing end of the shell and substantially at the juncture of said enlarged portion and reduced end of the insulator, the shell being in closely spaced relation with said reduced end from said gasket to a point adjacent the shell firing end to provide a substantially uniform narrow channel therebetween, and the shell being uniformly enlarged at the firing end to provide an enlarged opening into said channel.

GEORGE S WEINER'IH. 

